2, 2-dimethylol-1, 5-dihydroxypentane and derivatives thereof



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DERIVATIVES THEREF 1 i i No Drawing. Applications/inch 27, 1951, serial No. 2.17,sss`

5 Claims. (Cl. 26d-635) This invention relates to new and novel organic cornpouhds; and more particularly, to 2,2dirnethylol`l-,5-di 'hydroxypentane, derivatives thereof, andto methods'4 for the preparation of these new compositions of matter.` p

It has now been discovered that 2,2-dimetliylol-l,5'

`dihydroxypentane can be prepared by the I' condensation United States Patent() of `formaldehyde with -hydroxy valeraldehyde in the presence of an alkaline condensating agent and' that a substantially pure product may be obtained using either crude or refined -hydroxy valeraldhyde as the starting material. i

In a more specific embodiment of this invention, a -h`ydroxy valeraldehyde solution is slowly addedfto'a mixture consisting of formaldehyde and an alkalinecondensing agent, the mixture being maintained at a low temperature, i. e. within the range of 10-45 C. during this addition. External cooling means are used if necessary to'keep the temperature' off'the mixture lfrom rising beyond the aforesaid range in' order toprevenft theformaldehyde from entering into other'side reactions The amount of formaldehyde employed is in slight excess of that theoretically required to react wi'theach of the reactive hydrogens of the -hydroxy valeraldehyde and actually the molal ratio of formaldehyde to this compound is not less than l mol of formaldehyde'per mol of active hydrogen in the -hydroxy valeraldehyde. An aqueous formaldehyde solution containing about 5-40% by Weight of formaldehyde produces good results, best results `having been obtained by :the-use? of about a 25% `aqueous formaldehyde solution.

The mixture is heated ata moderate tempera-ture;vary.H ing between; about 55-60 C. unt-ilithe reaction issub.- stantiallyA completed and then neutralized with; formjc acid. This is followed by the concentration ofther'e- `sulting solution under reduced pressurejto obtain a sol-1d mixture containing 2,2-dimethylole1,5-dihydroxypentane and the sodium formate. While good results can be obtained when common mineral acids such as hydrochloric, sulfuric, phosphoric, etc. are employed in this `which'would-either seriously impair o'reven. prevent the completion of the desiredreaction. I 'Y neutralization step, the use of formi-c acid is preferred i to-,prevent any complications in the process resulting fromthe introduction of new ions into the solution.

The desired product is then separated from lthe metal `organic psaltby treating the concentrate with` av lower aliphatic alcohol such as butyl alcohol `or ethylalcoh'ol,

the 2,2-dirnethyl`ol#1,5-dihydroxypentane readiiydissolving in the solvent while the insoluble formate salt is subsequently removediby filtration. The 2,2-dimethylol- 1,5-dihydroxypentane is recovered by concentrating this ,ijrsppropyl alcohol, etc. While excellent results have ,alcoholic solution to a small volume thereby crystallizfing the desired product in relatively` pure forni.` Further process, etc.

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obtained by the use of any of these ,lower aliphatic alcohols, the use of .isopropyl alcohol is preferred because of litslow `cost and` general availability. A l v Itis obvious that valuable derivatives of thi'sj tetrahydi'iccompound can be prepared such as the Vhalo-derivatives, esters, acetals, partial esters, ethers, drying oils, alkyd resins, etc; One of these derivatives, i. e. the chlorosubstituted compound, has been prepared by Vreacting 2,Zdirhethylol-1,5-'dihydroxypentane with thionyl chlo- "rmide, in the presence of pyridine.y Other derivatives', `such as the esters, are prepared by the conventional methods of esterifying` 2, 2-dirnethylol-l, 5-dihydroxypentanel directly with various acids including'rosin and fatty acids (thelattercornpounds being used in excess quantities) while conducting the vreaction at a high temperature. Included 1in lthe term fatty acids, are acids such as cetic, formic, propionic, butyric, stearic, lauric, Vriiyristie, etc'.

2, `2vdi1nethyloll, 5^dihydroxypenta`ne is a" valuable ingredient of' drying oils, various surface coating final terials,.alk'yd resins, e'tc. The derivatives are likewise 'extremely useful in the preparation of drying oilsgplasticizers, surface active agents, intermediatesand-'the like, their specific properties depending on thefpa'rticular physical'` and chemical properties characteristic of'tliese derivatives;

:It should be mentioned that the derivatives ofi 2, Z-'dmethylol-1, 5"-dihydroxypentane naturally inlude awi'de fvar-iety; of Vcompouilds in" addition to' those indicated above because ofthe obvious possibilities olfered-by the 4 reactive hydroxy groups-in the compound, forexanple, and also in view of suchother factorsasthe `exteiinf the esteritication of these hydroxy groups,` that is esteri'- fication of 1, 2, 3 or all 4 of the hydroxy groups, the nature of the various acids used in the esteriication he following yexamples are illustrative of thelparfticularl compounds, compound mixtures and `concentrations lemployed in preparing 2, .'fdimethylol-l,l l.i-'diltiydroxypentane Vand some of its derivatives but are not-'to be construed as limiting since many variations may `be made't'herein without departing fromV the spirit or scope of theinvention. All parts and percentagesare by Weight unless otherwise indicated.

EXAMPLE i 9:1.'8 parts `(0.9 mol) of -hydroxy` valeraldehyde Iisl addedfto a mixture of 156 parts (1.17 mols) of `30% sodium hydroxide solution and 378 parts `(3.15 mols): of a cooled (18 C.) 25% `formaldehyde solution. This addition of the B-hydroxy v'aleraldehyde is -cont'inued for a period of 50 minutes during which time a temperature varying between about 12S-.30 C. is maintained. v(The delta compound is prepared by the procedure of Schniepp and Geller as reported `in the Journal j of the American Chemical Society, vol. 68, pp. 1646-8, 1946, and Ainvolves the acid hydrolysis of dihydropyran followed by vneuhours. After removal of the precipitated sodium formate` by, filtration, the solution is evaporatedunder reduced pressure to about one `half of its volume. The crystalline material that is `precipitated out on cooling `is re-A crystallizedfrom isopropanol and then dried. The productV obtained had a hydroxyl content of A40.8% and con; `tained 51.16% C and 9.22% H (calculated for 2, 2-dimetnyltlr snihydrqxypemane; 41.4% oH, 51.1% C,

EXAMPLE 1I Five hundred parts (5.95 mols) of dihydropyran is boiled with 2000 parts `of 0.02 N hydrochloric acid for about 1 hour, and the solution is then neutralized with sodium hydroxide. The mixture which cont-ainsapproximately 5.95 mols of -hydroxy valeraldehyde is then used (without purification) in the following preparation of 2, 2-dimethylol-1, 5-dihydroxy pentane.

' To 1953 parts (16.25 mols) of 25% formaldehyde solution and 419 parts of water is added 478 parts (6.03 moles) of 49.6% sodium hydroxide solution over a period of about 15-20 minutes, during which time the temperature is -maintained between about 15-25" C. Then the unpuried -hydroxyvaleraldehyde solution is .added to the mixture over a period of about one hour while a temperature of approximately 20 C. is maintained. After heating this mixture for about live hours at `a temperature ranging between 4about 55-60 C. during which ktime its formaldehyde content falls to about 0.7%, the solutionl is neutralized with formic acid and then distilled azeotropically with benzene to remove the water present. Ethanol is added to the residual syrup,

and the precipitated sodium formate is filtered oflt'. After the ethanol hasvbeen removed by distillation, 300 parts of dioxane is added, and the solution is heated under `reflux conditions for about three hours. The crystalline material which is obtained after the solutionhas been -standing for several days is washed with dioxane and then :dried at 80-85" C. After recrystallization from isopropanol and' drying at 55-60 C., 249 parts of material melting =at'9091 C. is obtained. The product has a .hydroxyl content of 39.4% (theory for 2, Z-dimethylol-l, 5-dihydroxypentane is 41.4%

EXAMPLE III Twenty-five parts by weight (0.1525 mol) of 2,2-dilmethylol-l, 5-dihydroxypentane is mixed with 48.2 parts V(0.61 mol.) of pyridine. Then 72.5 parts (0.61y mil) of thionyl chloride is added dropwise while the temperature of the mixture is held between about 70 and 80 C. The SOz'present is driven off by heating at about 100-105 C. for about onel hour. One hundred parts of water is added, and the solution is cooled to room temperature. One 200 and two 100 part portions of ethylene dichloride are used to extract the product from the reaction mixture. Following removal of the solvent, the residue is distilled at 124'131 C. under 2.5 mm. pressure, to obltainthe chloro-substituted product containing 57.2% Cl (theory- 60.1%

l By a similar reaction, other substituted halo derivatives may likewise be prepared.

EXAMPLE IV Teraacetate of 2,2-dimethylol-1,5-dhydroxypentane Twelve" grams (0.073 mol) of 2,2-dimethylo1-1, 5-dlhydroxypentane and 100 ml. of anhydrous pyridine were placed in a 50G-ml. ask and 40 g. (0.39 mol) of acetic anhydride was added. The mixture was allowed to reluxfor 1.5 hours. After cooling it was poured into 300 ml. `of-ice water.

y' T heaqueous suspension was extracted with 150 ml. of ether and the ethereal extract was washed with dilute hydrochloric acid until the washings were acidic. The extract was then washed with 25 ml. of water, 50 ml. of 5% sodium bicarbonate solution and finally with 50 ml. of water. After drying the ether solution over anyllous sodium sulfate, the ether was removed on a steam The resulting crude tctraacetate was distilled thrtough a Vigreaux-column and was collected `at 199200 C /4 mm. The yield of colorless material was 68%` Analyss.-Calcd. Sap. No. 672 mg. KOH/g.; Found: Sap. No., 672.2 mg. KOH/g.

The preparation of the tetraacetate of 2, 2-dimethylol-1, 5dihydroxypentane may be represented as follows:

CHQOH HOGHz-O-*CHaCHz'OHiOH-l-(CHgCO)2O GHzoH CHHOCOCH;

CBaCOOCHz-O-CHzCHaCHaOCOOH! .-i- 4CH3COOH CH2 O C O CH3 2,2-dimethylo1-1,-dihydroxypentane tetracetate Whereas this example illustrates a method for the preparation of the tetraacetate of 2, 2-dimethylol-1, 5dihy droxypentane, it is also quite possible to prepare partial esters, i. e. triacetate, diacetate, monoacetate, and also substitution products of the unesteriiied hydroxy groups, i. e. halo-derivatives, ethers, etc. of these partial esters. Likewise mixed esters, i. e. different ester groups such as for example a diacetate-diproprionate ester can likewise be prepared.

Reaction of 2, 2-dimethylol-1, 5dihydroxypentane with other aliphatic saturated acids such Vas propionic, butyric, stearic, etc. will produce the corresponding esters. `The esterification can be carried out by any suitable meth- ,od which may be selected from the methods well known -in the art.

EXAMPLE V The soy bean fatty acid ester is prepared by heating together with stirring, 30 parts (0.185 mol) of 2, 2-dimethylol-l, 5-dihydroxypentane and 127.8 parts (0.696 mol) of soy bean oil fatty acids (containing Cia acidslinoleic and linolenic lacids). The reaction is carried out by heating the ingredients together at a temperature of about 230 C. for about live hours. The product, a brown oil, has an acid number of 9.65 mg. KOH/g. The low acid number indicates that substantially com- -plete esterication has been effected.

EXAMPLE VI 15 parts (0.0927 mol) of 2, Z-dimethylol-l, 5-dihydroxypentane and 116.4 parts (0.348 mol) of rosin (containing abietic acid as the principal component) is heated together with stirring at a temperature varying between about 270-300 C. for approximately 8 hours to form the rosin ester. The ester possesses a saponication number of 51.9 mg. KOH/ g. and an acid number of 26.3 mg. KOH/g. Its hydroxyl content is 0.5%.

EXAMPLE VII The linseed oil fatty acid ester (containing esters of linoleic and linolenic acids) is prepared by reacting thirty parts (0.185 mol) of 2, 2-dimethylol-1, 5dihydroxy pentane at approximately 230 C. for about 4% hours with 193 parts (0.696 mol) of linseed oil fatty acids to form a drying oil with an acid number of 5.47 mg. KOH/g.

EXAMPLE VIII An alkyd resin is prepared by heating 119.3 parts by weight of soybean oil fatty acids, 50.3 parts of phthalic anhydride, and 50.1 parts of 2,2-dimethylol-1, 5-dihydroxypentane together at a temperature of about 230 C. `for about 15 hours. At the end of this time the resin has 'an acid number of `8 mg. KOH/g. A 70% solids solu- :The above described reaction canbe represented as follows:

' omtooncnmon aqueous formaldehyde solution containing about 25% by weight of formaldehyde and sodium hydroxide while CHAO CHzOH2)2OH Monostearate of tetra (-hydroxyethoxyethyl) ether of 2,2-dlmethylol-L-dihydroxypentone f EXAMPLE xiv Y In a Z50-ml. liask were placed 15.5 g. (.03 mol) of .tetra (-hydroxyethoxyethyl) ether of 2,2-dimethy1ol- 1,5-dihydroxypentane and 40 ml. of anhydrous pyridine. Sixteen grams (0.15 mol) of acetic anhydride was added and the mixture was reuxed for five hours. It was then cooled and poured into 200 m1. of ice water. The aqueous suspension of the ester was extracted with ether and the ethereal extract was washed with dilute hydrochloric acid until the washings were acid. It was then washed with water (50 mL), 5% sodium bicarbonate solution (50 m1.) and 50 ml. of water. The solution was dried over anhydrous sodium sulfate Vand the solvent removed under reduced pressure. The residue was a 'light tan liquid. y

Analysz's.-`Calcd.: Sap. No., 328 mg. KOH/g. Found: Sap. No., 346 mg. KOH/g.

The above described reaction can be represented as follows:

CH2(0 CHaOHahOH maintaining said mixtureat a temperature ranging between about `10"-'45 C., heating the resulting mixture until ,thereactionis' substantially complete, followed by neutralization thereof, concentrating the resulting solution, treating the concentrate thus obtained with a lower saturated aliphatic alcohol thereby separating the'desired material ,from the solution,`concentrating the resulting alcoholic solution to obtain 2,2-dimethylol-1,5-dhydroxypentane in a crystalline and substantially pure form.`

5. A process for preparing 2,2-dirnethylol-l,5di hydroxypentane in substantially pure form which comprises adding a -hydroxyvaleraldehyde solution to a mixture comprising an aqueous formaldehyde solution containing about 25% by weight of formaldehyde and sodium hydroxide while maintaining said mixture at a temperature of about 20 C.,.the molal ratio of said formaldehyde solution to said -hydroxyvaleraldehyde being not less than about 1:1, heating the resulting mixture until the reaction is substantially complete, neutralizing the reaction liquor with formic acid, concentrating said liquor,

l By reacting the above identied ether withl alkyl halides, aykyl sulfates, etc., other derivatives of the ether can likewise be prepared.

While various mod-ications of the above invention have been described, it is to be understood that other variations may be made in carrying out this invention, without departing from the spirit and scope thereof. Insofar as these modifications or changes are with-in the scope of the appended claims, they are to be considered as part of this invention.

I claim:

l. 2,2-dimethylo'l-1,5-dihydroxypentane.

2. A process for the preparation of 2,2-dimethyloll,5 dhydroxypentane which comprises reacting an aqueous solution of formaldehyde and -hydroxyvaleraldehyde in the presence of an alkaline condensing agent and then 4recovering the desired product from the reaction mixture. f 3. A process for the preparation of 2,2-dirnethylol1,5 dihydroxypentane which comprises reacting an aqueous solution of formaldehyde containing about 5-40% by weight of formaldehyde and -hydroxyvaleraldehyde in the presence of an alkaline condensing agent, the molal ratio of said formaldehyde solution to said -hydroxyvaleraldehyde being not less than about 1:1, and then re- ?covering the desired product Efrom the reaction mixture.

= 4.A process for the preparation of 2,2-dimethylol-L5- dihydroxypentane which comprises adding a solution of -hydroxyvaleraldehyde to a mixture comprising an olmo oHzoHmooooHs' Tetraacetate of tetra (-hydroxyethoxyethyl) other of 2,2d1methylol-1, -dihydroxypentane separating said 2,2 dimethylol 1,5 dihydroxypentane from the metal formate salt by treatment with np'ropy1 alcohol, concentrating the resulting alcoholic solution thereby crystallizing the desired product, and then obtaining said 2,2dimethylol1,5-dihydroxypentane in substantially pure form by recrystallization from an n-propyl alcohol solution. y

References Cited in the file of this patent OTHER kREFERENCl-ES Chem. Abst., vol. 42, page 2267i.

Bull. Soc. Chem. de France (1947), Paul, pp. 165-168.

Chemical Abstracts, vol. 44 (1950), page 113C; (Abstract of Annalen 562 (1949), pp. -136, article by Sefken). 

1. 2,2-DIMETHYLOL-1,5-DIHYDROXYPENTANE.
 2. A PROCESS FOR THE PREPARATION OF 2,2-DIMETHYLOL-1,5DIHYDROXYPENTANE WHICH COMPRISES REACTING AN AQUEOUS SOLUTION OF FORMALDEHYDE AND $-HYDROXYVALERALDEHYDE IN THE PRESENCE OF AN ALKALINE CONDENSING AGENT AND THEN RECOVERING THE DESIRED PRODUCT FROM THE REACTION MIXTURE. 